SINGAPORE, Nov 20 (Reuters) - Oil trader Trafigura placed the lowest offer and is likely to win an import tender by the Ethiopian Petroleum Supply Enterprise for up to 1.85 million tonnes of gasoil and gasoline for delivery in 2018, several traders said on Monday.

The east African importer was seeking 1.2 million tonnes to 1.5 million tonnes of 500 parts per million sulphur gasoil and 280,000 tonnes to 350,000 tonnes of 92-octane gasoline for delivery over next January to December.

Trafigura placed the lowest offer of $3.69 a barrel over Middle East 500ppm sulphur gasoil quotes for gasoil and $3.97 a barrel over benchmark Singapore gasoline quotes for the gasoline cargoes, according to traders who did not want to be identified as they were not authorised to speak with media.

Two other companies who participated in the tender were PetroChina and Vitol, they added.

The tender is expected to be officially awarded later on Monday or on Tuesday, according to one of the traders.

Trafigura declined to comment, while officials at Ethiopian Petroleum Supply Enterprise and PetroChina could not immediately be reached for comment.

Vitol had previously told Reuters that it would not typically comment on trade activity. (Reporting by Jessica Jaganathan; Editing by Joseph Radford and Manolo Serapio Jr.)